1. Field of Invention
The present invention relates to an optical-coupler reinforcing member and an optical-coupler reinforcing method.
2. Description of Related Art
Generally, an optical-fiber coupler is produced through a process in which an optical-fiber coupler body formed by melt-drawing is fixed by using a fixing member having substantially the same coefficient of linear expansion as that of a quartz optical fiber. FIG. 4 (PRIOR ART) shows an example of the conventional optical-fiber coupler.
As shown in the drawing, an optical-fiber coupler body 103 having an optical-fiber tapered portion 102 in which optical fiber strands 101 are mutually fused is plate-like formed, and fixed so as to be sandwiched between a first and second fixing members 105 and 106 each having at its surface a groove portion 104 having a predetermined shape. The fixing method utilized is an adhesion method using, for example, an epoxy group adhesive or an ultraviolet-ray setting adhesive.
The optical-fiber coupler according to the foregoing prior art is fixed by using an adhesive which has provided for the following problems. The conventional method comprises melt-drawing optical fibers, making a quartz casing come into contact with the melt-drawn fibers, and application of an adhesive onto opposite end portions of the casing so as to integrate the quartz casing and the optical fibers with each other. This conventional method requires a separate step of application of the adhesive. Even the quickest setting adhesive requires a setting speed approximately 15 minutes. This step of applying and setting the adhesive makes the attachment of the reinforcing casing the slow step in the process; often slowing production.
This delay makes it crucial to further ensure protection against outside air or moisture from contaminating the attachment process after fixing of the plate-like protection member.
In the case of using an ultraviolet-ray setting adhesive, there is the further complication of utilizing expensive machinery such as an ultraviolet light source or the like.
In view of the foregoing, an object of the present invention is to provide an optical-coupler reinforcing member in which work is simplified and production and manufacturing time is shortened. Further, the present invention provides an optical-complex reinforcing member with improved strength and method for producing same.